Dial lighting



Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE mu. LIGHTING Ray L. Triplett, Bluflton, Ohio Application June 20, 1938, Serial No.214,ec9

' 2 Claims. (01. 240-21) My invention relates to illuminating dials for instruments and the like.

It is the object of my invention to provide means of illuminating a translucent or transparent plate utilized as a dial plate.

It is the object of my invention to locate a light source adjacent the ground or frosted edge of the light transmitting dial plate.

It is an object of my invention to provide means 10 of directing and reflecting the light against said edge to increase the illumination from the source of illumination or to prevent the waste'of light.

It is a further object of my invention to provide in such a connection a combined means of 15 housing an electric lamp and of supporting the sheet illuminated by it.

It is a further object of my invention to provide such a housing which is readily accessible for removing and replacing the electric lamp. go Referring tothe drawing:

Figure 1 is a perspective of a complete instrument showing the location of the plurality of light sources adjacent the bottom ground edge of the dial plate to be illuminated by the lamps.

Figure 2 is a section on the line 2-2 of Figure 1, looking in the direction of the arrows.

Figure 3 is a perspective of a portion of the side wall and bottom of the illuminated dial plate.

Referring to the drawing in detail, I is a housing of an instrument, preferably of metal. Mounted on the face of this housing is a translucent or transparent dial plate 2 that it is desired to illuminate. This plate is supported along its bottom edge within the slots 3 formed by the flanges 4 of the lamp housing 5 that is mounted upon the metal or Bakelite casing I by the hooks 6.

The lower edge I of the plate 2 rests in these semi-circular transverse slots 3 in the drum-like 40 housing 5. The rear of this housing is closed by the wall I, and the front by a closure 8. Within the enclosure is a lamp socket 9 and an electric lamp in directly beneath the lower edge I of the plate 2. This edge is preferably frosted, as at H. 45 This edge may be sandblasted, pitted or otherwise arranged to diffuse the light through the plate 2.

Thebottom of the housing 5 is provided with a removable plate l2 to permit access to the in- 50 terior of the casing 5. It will be understood that there is a variety of other ways by which this casing may be built. The interior of the casing serves as a reflector for reflecting the light through the bottom edge 65 'I of the plate 2.

Thus these casings 5 act as supports for the plate 2 just above the lamps l0, which directs the light upwardly through the plates to illuminate the entire plate. Thus a proper distribution of light is secured by this uniform illumina- ,tion so that all the printing is uniformly seen as it appears upon the dial plate 2. 5

The housing i may-be of plastic or metal, or any other opaque material. The exact construction of this housing is not important. Likewise the housing of the lamps may be of any material that may be plated on the interior to increase 10 the illumination as desired. They are preferably made of brass, aluminum or similar material for conducting heat from the light bulb to the exterior of the case 5.

The loweredge I of the plate 2 may be either ground, sandblasted or etched. Any method is satisfactory, so long as a uniform distribution of light is over the entire bottom and therefore there is a uniform distribution of light throughout the scale appearing upon the plate 2. 7 go It will be understood that I desire to comprehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

It will be understood that where/the bottom edge is referred to in the specification and claims herein, that this is merely a generic term as the same result can be achieved with any edge of the sheet, whether bottom, top or sides. Either one edge or multiple edges may be used. Any edge will so function as long as it is roughened to give the proper diffusion and distribution of light.

Having thus fully described my invention, what. I claim as new and desire to secure by Letters Patent, is:

1. In combination, a plurality of cylindrical lamp housings having transverse semi-circular slots and associated positioning flanges therein, a dial plate of translucent or transparent material having a light diffusing lower edge, said 4 plate being mounted within said slots and supported thereby, lamps in each of s'aid'housings directly positioned beneath and adjacent to sai lower edge of said dial plate.

2. In combination, a. plurality of cylindrical lamp housings having transverse semi-circular slots and associated positioning fienges therein,

a dial plate of translucent or transparent material having a roughened finish edge, said plate being mounted within said slots and supported thereby, lamps in each of said housings directly positioned beneath and adjacent tosaid lower edge of said dial plate, and means in said housings adapted to be removed therefrom to permit access to the interior thereof.

RAY L. TRIPIEIT. 

